This past Monday (April 22, 2019) at 0050z on 12137 kHz I stumbled on a new, to me, and as far as I know previously unreported, Russian M12 numbers station transmission. The callup was 891 891 891 891 1, indicating the 0050z transmission I heard on 12137 kHz was probably the last of three transmissions that day, with earlier transmissions at 0010z and 0030z on higher frequencies, with 100's digit of 8 and 9 and last two digits of 37.
So began the hunt, each night, to determine what days this station is active. For M12 it is common for their to be two active days per week for a given schedule. ANd this morning I found the other transmissions.
It appears the schedule is on Mondays and Fridays, at 0010z, 0030z, and 0050z, on frequencies of 14837 kHz (at 0010z), 13937 kHz (at 0030z), and on 12137 kHz (at 0050z).
Unfortunately, we are near the end of the month, and there is only one more day this month this station should be active on this schedule, that would be next Monday, April 29. After that it will still probably be active on Mondays and Fridays, but on a new set of frequencies, and possibly in a new time slot, will have to search next Friday to find the new schedule.
It is very likely that this Monday / Friday M12 is transmitted from the same location as the other known Asiatic M12 on Tuesday / Thursday, and the V07 on Sunday. There also used to be another M12 from the same source on Wednesday and Saturday, but as far as I know that schedule is no longer active.
T!